Sec. 23.143 - General.

(a) The airplane must be safely controllable and maneuverable during all flight phases including --

(1) Takeoff;

(2) Climb;

(3) Level flight;

(4) Descent;

(5) Go-around; and

(6) Landing (power on and power off) with the wing flaps extended and retracted.

(b) It must be possible to make a smooth transition from one flight condition to another (including turns and slips) without danger of exceeding the limit load factor, under any probable operating condition (including, for multiengine airplanes, those conditions normally encountered in the sudden failure of any engine).

(c) If marginal conditions exist with regard to required pilot strength, the control forces necessary must be determined by quantitative tests. In no case may the control forces under the conditions specified in paragraphs (a) and (b) of this section exceed those prescribed in the following table: 

------------------------------------------------------------------------
    Values in pounds force applied to the
               relevant control                 Pitch     Roll     Yaw
------------------------------------------------------------------------
(a) For temporary application:
  Stick......................................       60       30  .......
  Wheel (Two hands on rim)...................       75       50  .......
  Wheel (One hand on rim)....................       50       25  .......
  Rudder Pedal...............................  .......  .......      150
(b) For prolonged application................       10        5       20
------------------------------------------------------------------------

[Doc. No, 4080, 29 FR 17955, Dec. 18, 1964, as amended by Amdt. 23-14, 38 FR 31819, Nov. 19, 1973; Amdt. 23-17, 41 FR 55464, Dec. 20, 1976; Amdt. 23-45, 58 FR 42156, Aug. 6, 1993; Amdt. 23-50, 61 FR 5188, Feb. 9, 1996]